The invention relates to an apparatus for positioning optical components in an optical device, comprising a holding device having a plurality of receptacles on which the optical components are held, wherein the holding device is rotatable into a plurality of predetermined rotary positions, in which rotary positions respectively one of the optical components is arranged in a target position, a motor comprising a motor shaft for rotating the holding device, a controller for controlling the motor and a transmitting mechanism for transmitting the rotary movement of the motor shaft into a rotary movement of the holding device. Further the invention relates to a microscope having such an apparatus.
Apparatuses of the aforementioned type are for example used in microscopes to pivot optical components such as objectives or filter blocks, which are held on a rotary disk, individually into a target position located in a beam path. Thereby it is important to bring the optical components into the target position as fast, noiseless and accurately as possible.
Conventional positioning apparatuses usually use gear motors which drive the rotary disk. Thereby a mechanical latching is assigned to each optical component, e.g. formed as latching notch formed on the disk, into which a spring-loaded ball latches. If the gear motor is provided with a freewheel, the disk can slightly freely move in the region of the target position, whereby the ball latches into the latching notch. Such a positioning apparatus is e.g. described in EP 1 403 672 B1. Regarding prior art further reference is made to DE 1 262 121 A, DE 296 04 667 U1 and DE 199 24 686 A1.
In positioning apparatuses of the aforementioned type it is a disadvantage that comparatively strong motors have to be used. This is due to the fact that in case of a change of position the motor first has to turn the disk out of the latching position, in which the disk is fixed. For this, a substantially higher force is necessary than would be necessary for only rotating the disk between the latching positions. Furthermore, with conventional positioning apparatuses there are unwanted noises and mechanical vibrations, when the spring-loaded ball runs over a latching notch with high speed during a rotary movement of the disk running over individual latching positions. This leads to impact stress of the notch flanks, when the ball entering the respective latching notch impinges on the notch flank being directed opposite to the moving direction.
Finally it is a disadvantage with conventional positioning apparatuses that the latching notches have to be formed (e.g. milled) on the rotary disk in precise positioning relative to the receptacles in which the optical components are held. A subsequent correction of positioning errors such as they occur e.g. with inclined optical components is not possible.
It is the object of the invention to provide an apparatus of the aforementioned type for positioning optical components in an optical device such that shifting of the optical components is as low-noise and vibration-free as possible. Further it is the object of the invention to provide a microscope in which optical components can be positioned with low noise and vibration-free.